Rocker circuit design and radial drilling machine description
According to the relay control principle, the radial drilling machine is driven by multiple motors. The main shaft motor M1, rocker arm lifting motor m2, hydraulic pump motor m3 and cooling pump motor M4 are analyzed. According to the electrical control principle, there are 11 input elements, 6 buttons and 5 switch switches; 9 output components, 5 contactor coils, 1 solenoid valve and 3 signal lights. The thermal relay of the relay control circuit is not used as an input element. It is convenient to connect the contact points in series with the contactor coil circuit, which can save the output points.
According to the I / O distribution, the I / O terminal sub wiring diagram is made. The input side of the 3 sub wiring diagram uses DC 24 V, and the output side uses AC 220 V, so it is more convenient to directly drive AC contactor and solenoid valve. However, the normally closed contacts of main electrical appliances are all input with normally open contacts, which makes programming simple. The normally closed contacts of thermal relays are connected in series in the coil circuit of contactors for overload protection. The normally closed contacts of contactors are connected in series into the coil circuit for interlocking protection, which can increase the system reliability. The input and output of PLC adopt photoelectric isolation, which enhances the anti-interference ability.
Program design and description of radial drilling machine
According to the control requirements of radial drilling machine and the control logic of relay contactor, combined with the port distribution of PLC, the PLC control program is reformed.
PLC control principle of radial drilling machine
(1) Starting and stopping of spindle motor
Press start button SB2 (non self-locking), input point X2 is closed, output point Y1 is powered on, coil of contactor KM1 is powered on, Hl3 indicator light is on, and spindle motor ml is powered on. Press stop button SB1 (non self-locking), input point Xi is closed, output point Y1 is powered off, corresponding contactor KM1 loses power, coil is released, spindle motor ml stops running, and indicator light Hl3 is off.
(2) Rocker arm lifting control
Release rocker arm movement process: press up button Sb3 (non self-locking), input point X3 is closed (or press down button Sb4 (non self-locking), input point X4 is closed), auxiliary relay R1 is energized, its auxiliary normally open contact is connected, output point Y4 and output point y6 are connected, auxiliary relay R2 is connected, contactor km4 is powered on, and coil is closed, The hydraulic pump motor m3 runs forward and sends out positive pressure oil. Then the solenoid valve YV is energized, the coil is closed, and the rocker arm is released.
Rocker arm up (down) movement process: after the rocker arm up (or down) release action is completed, press travel switch SQ2, its corresponding input normally closed contact X22 is disconnected, output point Y4 is disconnected, contactor km4 is powered on, coil is closed, hydraulic pump motor m3 is cut off and rocker arm is always in loose state; at the same time, input point X22 corresponding to normally open contact is closed, and output point Y2 (or Y3) is connected, When the contactor km2 (or KM3) is electrified, the coil is closed, and the rocker arm lifting motor M2 runs in the positive direction (descending is reverse operation), and the rocker arm is directly dragged up (or down).
The movement process of clamping rocker arm: when the rocker arm rises (or descends) to the desired position, release the button Sb3 (or Sb4), the corresponding input point is disconnected, the auxiliary relay R1 is not electrified, the output point Y2 (or Y3) is de energized, the contactor km2 (or KM3) is powered on, the coil is closed, the rocker arm lifting motor M2 is powered off, and the corresponding rocker arm lifting is no longer operating; At the same time, turn on the timer T1, and the timer will act after 3 seconds of power on. The normally open contact of the timer will be closed, the input point Y5 will be closed, the contactor km5 will be powered on and the coil will be closed. Hydraulic pump motor m3 runs in the opposite direction and sends out pressure oil in the opposite direction to clamp the rocker arm. After the clamping action is completed, press down the travel switch SQ3, the corresponding input point x23 of the travel switch is released, the input points Y5 and y6 lose power, and the contactor km5 and solenoid valve YV stop m3 due to the coil release.
(3) Control of loosening and clamping headstock and column
Close the spindle box release button sb5, input point X5 is connected, output point Y4 is closed, contactor km4 is powered on, coil is closed, hydraulic pump motor m3 is running forward, and solenoid valve YV is not working. Loosen headstock and column. When the travel switch sq4 is not pressed, the normally closed contact is closed, the indicator light HL1 is powered on and the whole headstock and column are released.
Close the spindle box clamping button sb6, the input point X6 is closed, the output point Y5 is connected, the corresponding contactor km5 is powered on, the coil is closed, the hydraulic pump motor m3 is in reverse operation, the solenoid valve YV is still not powered, the headstock and column clamping = at the same time, the travel switch sq4 is pressed, and the corresponding normally closed point is disconnected, When the indicator light HL1 loses power, the output point corresponding to the normally open contact is closed, and the indicator light HL2 is on, which completes the clamping of the whole headstock and the column.